Submarine elongate structures, and in particular submarine pipelines, can become unstable through exposure to environmental influences, particularly hydrodynamic loads arising from underwater currents and wave action. These hydrodynamic loads typically increase in regions of shallow water. The combination of extreme environmental loads and shallow water are present in Australian waters, typically on the North West Shelf off the West Australian coast.
Various systems are currently utilised for submarine pipeline stabilisation, including weight coatings on pipelines, coverings on pipelines, installation of pipelines in trenches in the seabed, and securing pipelines to the seabed by way of mechanical anchors. Various deficiencies and problems can be associated with each of these stabilisation systems. For example, weight coating requirements for pipelines can be very high or impracticable. Trenching of pipelines is required to be deep in the seabed. Coverings over the pipeline need to be thick and of adequate weight, and in some cases the covering material may itself be unstable. Mechanical anchors of high capacity are required at close intervals to secure the pipelines to the seabed.
While the abovementioned systems can be utilised in many situations, there are locations where the cost involved can be very high or indeed prohibitive, and the installation procedure can be time-consuming.
It is against this background, and the deficiencies and problems associated therewith, that the present invention has been developed.